环形内支撑深基坑开挖引起的变形及对既有建筑物影响研究

发布时间：2018-04-17 18:24

本文选题：水平变形 + 土层位移　；参考：《西南交通大学》2017年硕士论文

【摘要】：近年来,随着城市的快速发展,出现了大量的深基坑工程。在城市土地的大量开发利用过程中,基坑工程往往出现在工程环境较复杂的区域。由于工程环境对变形有着严格的要求,故有必要开展基坑开挖引起的变形特性研究。本文以信和2B期项目为工程背景,对环形内支撑深基坑开挖引起的变形及对既有建筑物影响进行了相关研究,主要研究内容和成果如下:(1)对环形内支撑基坑开挖引起的围护结构水平变形特性、周围地表变形特性以及工程周边建筑物变形特性展开研究。在三道环形内支撑作用下,围护结构水平变形形态呈抛物线型,周围地表沉降形态主要呈凹槽型;周边建筑物沉降表现为不均匀沉降,其水平侧移朝着基坑方向发展。(2)对环形内支撑基坑开挖引起的周围土层位移特性展开研究。基坑开挖对周围土层的影响范围随深度呈三角形分布形式,影响范围在地表最大,随着深度的增加渐渐减小,在围护结构的底部影响范围趋于0。(3)研究环形内支撑结构支撑位置对围护结构水平变形特性、周围地表变形特性以及工程周边建筑物变形特性的影响。第一道环形内支撑靠近地表,围护结构顶端位移变小,靠近基坑边缘的地表沉降变小,临近的建筑物变形变小。(4)从建筑物位置以及基础埋深方面研究基坑开挖引起的临近建筑物的变形。对于临近既有建筑的基坑工程,当既有建筑基础底部与基坑底部的高差和既有建筑与基坑距离的比值(即△H/d)满足一定条件时,可认为基坑开挖不会影响临近的建筑物,对类似本文所研究的基坑工程,△H/d小于0.4～0.6时,可认为基坑开挖不会影响临近的建筑物。
[Abstract]:In recent years, with the rapid development of cities, a large number of deep foundation pit projects have emerged.In the process of extensive development and utilization of urban land, foundation pit works often appear in areas where the engineering environment is more complex.Because the engineering environment has strict requirements for deformation, it is necessary to study the deformation characteristics caused by excavation of foundation pit.In this paper, based on Xinhe 2B project, the deformation caused by deep foundation pit excavation with annular bracing and its influence on existing buildings are studied.The main research contents and results are as follows: (1) the horizontal deformation characteristics of the retaining structure, the surrounding surface deformation characteristics and the deformation characteristics of the surrounding buildings caused by the excavation of the ring-supported foundation pit are studied.Under the action of three annular inner supports, the horizontal deformation of the envelope structure is parabolic, the surface settlement around it is mainly concave, and the settlement of the surrounding buildings is uneven settlement.The displacement characteristics of surrounding soil layer caused by the excavation of annular inner braced foundation pit are studied.The influence range of foundation pit excavation on the surrounding soil layer is triangular distribution with depth, the influence range is the largest in the surface, and gradually decreases with the increase of depth.The influence of bracing position on the horizontal deformation characteristics, the surrounding surface deformation characteristics and the deformation characteristics of the surrounding buildings is studied.The first ring of inner support is near the surface, and the top displacement of the enclosure becomes smaller, and the surface settlement near the edge of the foundation pit becomes smaller.The deformation of adjacent buildings caused by excavation of foundation pit is studied in terms of the location of the building and the depth of the foundation.When the height difference between the base of the existing building and the bottom of the foundation pit and the ratio of the existing building to the foundation pit (that is, H / d) satisfy certain conditions, it can be considered that the excavation of the foundation pit will not affect the adjacent building.For foundation pit engineering similar to the one studied in this paper, when H / D is less than 0.4 ~ 0. 6, it can be considered that the excavation of foundation pit will not affect the adjacent buildings.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU753

【参考文献】